Mortar safety device for preventing double loading

ABSTRACT

A safety device for preventing feeding a mortar round into a barrel already containing a round. A tripping arm of a bell crank extends into the barrel of a mortar and permits one mortar round to enter the barrel. The tripping arm then locks to prevent a second round from entering the barrel. The firing of the first round unlocks the tripping arm to permit a subsequent firing of the mortar.

Bite States Albatys atent MORTAR SAFETY DEVICE FOR PREVENTING DOUBLELOADING [72] Inventor: Zigmund M. Albatys, Louisville, Ky.

{73] Assignee: The United States of America as represented by theSecretary of the Navy [22] Filed: June 23, 1971 [21] Appl. No.: 155,990

' [52] U.S. C1. ..z; ..89/1 F, 42/l F; 89/37 C [51] int. Cl. ..F4lf l/06[58] Field of Search ..89/1 F, 1, l4; 42/l F, 76

[56] References Cited UNITED STATES PATENTS 1,405,291 1/1922 Conill..89/37 C 51 Oct. 17, 1972 3,481,246 12/1969 Snyder ..42/lF PrimaryExaminer-Samuel W. Engle Attorney-R. S. Sciascia et al.

[5 7] ABSTRACT A safety device for preventing feeding a mortar roundinto a barrel already containing a round. A tripping arm of a bell crankextends into the barrel of a mortar and permits one mortar round toenter the barrel. The

tripping arm then locks to prevent a second round from entering thebarrel. The firing of the first round unlocks the tripping arm to permita subsequent firing of the mortar.

6 Claims, 4 Drawing Figures INVENTOR. ZIGMUND M. ALBATYS M ATTOR EYSPATENTEDucr 11 1912 SHEET 1 BF 2 PATENTED B l 7 I97? 3.698.282

SHEET 2 [IF 2 Fig.4

INVENTOH. Z IGMUND M. ALBATVS y y/ M ATTORNEYS MORTAR SAFETY DEVICE FORPREVENTING DOUBLE LOADING STATEMENT OF GOVERNMENT INTEREST The inventiondescribed herein may be manufactured and used by or for the Governmentof the United States of America for governmental purposes without thepayment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION A mortar, such as the 60 mm or 81 mm mortarused by the military, is a relatively simple weapon and consistsbasically of a base plate, a barrel and a firing pin. The firing pinmight be either of the fixed type or a movable type which is actuated bya trigger assembly. In a'mortar having a fixed firing pin, the roundslides down the barrel, strikes the firing pin and is then ejected. Inthe event of a misfire, the dud can be immediately removed by tippingthe barrel and letting the round slide out. With a fixed firing pin, thechances of double loading is not too great, as the round is not loadeduntil it is to be fired.

With a triggered firing pin, however, a mortar may be loaded aconsiderable time in advance of firing, and there is always a chancethat a second round might be inserted into a loaded mortar barrel. Uponactuation of the trigger, a double-loaded mortar will usually explodeand cause serious injury or death to personnel near the weapon.Heretofore, there has not been any devices used by the military toprevent the loading of a second round into a loaded mortar.

SUMMARY OF THE INVENTION The present invention consists of an auxiliaryunit which is mounted to a mortar near the muzzle end and is designed toprevent double loading of a mortar. As mortar rounds have at least twosections with outside dimensions only slightly smaller than the bore ofthe barrel, that is, a fin section and a body section, it is necessarythat a tripping lever be actuated at least twice before locking.

In the present invention, a tripping arm of a bell crank extends througha slot into the mortar barrel and a selector switch is provided topermit the tripping arm to be actuated either two or three times, andthen it locks to prevent any further tripping, such as that done byloading a second round into the barrel. Upon firing of the first round,the round actuates the tripping arm in a reverse direction and unlocksthe tripping arm to permit a new round to be loaded. As some rounds havethree enlarged diameters, a selector switch is provided so that thetripping arm can be locked after either two or three trips, as desired.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top view showing apreferred embodiment of the present invention attached to a mortar;

FIG. 2 is a side view, partially in section, of the preferred embodimentof the present invention;

FIG. 3 is a top view, partially in section, of the preferred embodimentof the present invention; and

FIG. 4 is a top view of a mortar round having three enlarged diameters.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of thedrawing, there is shown a mortar 11 having a barrel 12 attached to abase plate 13 and a firing pin 14 for detonating the primer of a mortarround. A safety device 15 is attached to the outside of barrel 12 toprevent the loading of a second round into barrel 12 that contains afirst round.

Referring now to FIGS. 2 and 3 of the drawing, there is provided ahousing 16 which is attached, as by screws, to barrel 12 near the muzzleend. A first bell crank 17 is pivotally connected to housing 16 on shaft18 and has arms 21 and 22. A stop 23 is provided on housing 16 to limitthe clockwise rotation of bell crank 17. Arm 22"is'fo'rked'and a secondbell crank 24 is attached in the forked end of bell crank 17 by shaft25. Arm 22 is provided with a cam surface 26 and a cam surface 27 isprovided on bell crank 24. A spring 28 is provided around shaft 25 toretain bell crank 24 in a centered position relative to hell crank 17.Bell crank 24 is provided with two arms 31 and 32, with arm 31 extendingthrough slot 33 in barrel l2 and into the bore of barrel 12.

An indexing arm 34 is pivotally attached by shaft 35 to housing 16 andhas one end 36 engageable with arm 32 of bell crank 17. An indexingcylinder 37 is rotatably mounted about shaft 38 which is stationarilyattached to housing 16. A notch 39 is provided in the periphery ofindexing cylinder 37 and end 41 of indexing arm engages notch 39.Indexing arm 34 functions as a rocker arm and clockwise rotation ofindexing arm 34 is limited by stop 42 on housing 16. A spring 43 isprovided to bias indexing arm 34 against stop 42.

A ratchet arm 44 is rotatably attached to housing 16 by shaft 45 and end46 of arm 44 is engageable with arm 21 of bell crank 17.Counterclockwise rotation of ratchet arm 44 is limited by stop 47 onhousing 16. A spring 48 is provided to bias arm 44 against stop 47. Alocking cylinder 49 is rotatably mounted on shaft 38 and end 51 ofratchet arm 44 is engageable with notches 52 in the periphery ofcylinder 49. Cylinder 49 has one fixed tooth 53 and three pivotal orratchet teeth 54 and these teeth are engageable with a single tooth 55on the side of indexing cylinder 37. As best shown in FIG. 3 of thedrawing, a pin 56 is attached to stationary shaft 38 and passes througha skewed slot 57 in indexing cylinder 37. As shaft 38 and pin 56 arestationarily mounted with respect to housing 16, rotation of indexingcylinder 37 by movement of arm 34 will impart lateral movement ofindexing cylinder 37 so that tooth 55 can engage the teeth on lockingcylinder 49.

A spring 58 is provided around shaft 38 and has one end attached tolocking cylinder 49 and the other end attached to housing 16. Clockwiserotation of locking cylinder 49 by indexing cylinder 37 winds spring 58and, upon disengagement of indexing cylinder 37 with locking cylinder 49and release of ratchet arm 44 from notches 52, spring 58 drives lockingcylinder 49 so that stop 59 on looking cylinder 49 engages stop 61 onhousing 16.

Most mortar rounds which are presently used by the military have twoenlarged diameter portions which trip arm 31 of bell crank 24. A few,however, have three enlarged diameter portions, such as theanti-personnel cartridge 62 shown in FIG. 4 of the drawing, which has afin assembly 63, a star washer 64 and an explosive body 65. A selectorknob 66 is provided, and when pointer 67 points to TWO, a stop arm 68 onshaft 69 is in position to engage stop 59 on locking cylinder 49. Thedistance between stop 61 and stop 68 is such that ratchet arm 44 willratchet twice in notches 52 of indexing cylinder 37. When knob 66 isturned so that pointer 67 points to THREE, stop 71 is in position toengage stop 59 on locking cylinder 49. The distance between stop 61 andstop 71 is such that ratched arm 44 will ratchet three times in notches52 of indexing cylinder 37. When stop 59 is positioned against eitherstop 68 or stop 71, further rotation of locking cylinder 49 isprevented. Arlocking pin 70 is provided to retain selector knob 66 in alocked position.

As best shown in FIG. 2 of the drawing, a pointer 72 is attached tolocking cylinder 49, and a window 73 is provided in housing 16 forviewing pointer 72. When stop 59 is against stop 61, pointer 72indicates a load condition, and when stop 59 is against either stop 68or 71, a fire condition is indicated. In the event that a round ispresent in barrel 12, pointer 72 will indicate a fire condition, thusproviding a warning that another round should not be loaded, but inaddition, bell crank 24 will not pivot sufficiently for arm 31 to becomeclear of the bore of barrel 12, and thus arm 31 will prevent a secondround from entering barrel 12.

OPERATION In operation, when a round having two enlarged diameterportions is to be fired, selector knob 66 is turned so that pointer 67points to TWO and then locking pin 70 is used to lock knob 66 againstany additional rotation. Stop arm 68 is now in a position to be engagedby stop 59. Pointer 72 will indicate a LOAD condition. As round 74starts its descent down barrel 12, fin assembly 75 will strike arm 31causing bell crank 24 to be pivoted about shaft 25. Arm 32 of bell crank24 will engage end 36 of indexing arm 34 and cause indexing arm 34 torotate about shaft 35 and turn indexing cylinder 37. As shaft 38 and pin56 are stationary, rotation of indexing cylinder 37 by indexing arm 34will cause lateral movement of indexing cylinder 37 and tooth 55 oncylinder 37 will engage tooth 53 on locking cylinder 49. Continuedrotation of indexing cylinder 37 will cause locking cylinder 49 toratchet. When fin assembly 75 clears arm 31, spring 28 will return bellcrank 24 to its original position. Spring 43 will also return indexingarm 34 against stop 42 and indexing arm 34 will return indexing cylinder37 to its original position. it can thus be seen that locking cylinder49 has been rotated against the force of spring 58 and stop 59 will bepositioned midway between stops 61 and 68. When the body portion 76 ofround 74 engages arm 31, the ratcheting of locking cylinder 49 will berepeated and stop 59 will move against stop arm 68. Pointer 72 will nowbe indicating a fire condition.

When round 74 is fired from the mortar, the body portion 76 of round 74will strike arm 31 and cause bell crank 17 to be rotated in acounterclockwise direction. Arm 21 of bell crank 17 will pivot ratchetarm 44 about shaft 45, and end 51 of arm 44 will disengage from notch52. Spring 58 will then return locking cylinder 49 to its startingposition with stop 59 being in engagement with stop 61. Pointer 72 willagain indicate a LOAD condition.

Until round 74 is fired, pointer 72 will indicate a fire condition,which will warn that an additional round 74 should not be loaded intobarrel 12. In the event, however, that an attempt is made to load, arm31 of bell crank 24 will not pivot sufficiently for arm 31 to clear thebore of barrel 12. Arm 32 will engage indexing arm 34 and partiallyrotate indexing cylinder 37 so that tooth 55 will engage ratchet tooth54 on locking cylinder 49. Locking cylinder 49 will not turn, however,and indexing cylinder 37 will stop thus preventing arm 31 from clearingthe bore of barrel 12.

When a mortar round having three enlarged diameters is to be fired, suchas the anti-personnel cartridge 62 which is shown in FIG. 4 of thedrawings, selector knob 66 is turned to THREE. Stop arm 68 is rotated bythe turning of knob 66 and is not in position to be engaged by stop 59on locking cylinder 49. Stop 59 is then free to travel until it strikesstop 71. The distance between stops 61 and 71 is such that lockingcylinder 49 will ratchet three times, that is, once for each enlargeddiameter on round 62.

I claim:

1. A safety device for preventing the loading of a mortar round into abarrel already containing a mortar round comprising,

a housing adaptable for mounting to the outside of a mortar barrelhaving a slot adjacent to its muzzle end,

a first bell crank pivotally attached to said housing having first andsecond arms,

a second bell crank pivotally attached to said first arm of said firstbell crank and having a tripping arm extending through said slot of saidbarrel and having a driving arm,

an indexing cylinder rotatably mounted in said housa locking cylinderrotatably mounted in said housing and having a plurality of ratchetnotches, said locking cylinder having means for intermittently engagingsaid indexing cylinder,

an indexing arm pivotally attached to said housing having one endengageable with said indexing cylinder and one end engageable with saiddriving arm of said second bell crank,

a ratchet arm pivotally attached to said housing having one endengageable with said ratchet notches in said locking cylinder and oneend engageable with said second arm of said first bell crank, and

stop means for limiting the amount of rotation of said locking cylinder.

2. A safety device for preventing the loading of a mortar round into abarrel already containing a mortar round as set forth in claim 1 whereinsaid stop means includes a first stop attached to said locking cylinderand second and third stops attached to said housing, said first stopbeing movable between said second and third stop.

3. A safety device for preventing the loading of a mortar round into abarrel already containing a mortar round as set forth in claim 2 whereinsaid third stop includes a stationary member and a movable member roundas set forth in claim 1 wherein said indexing cylinder has one geartooth and said locking cylinder has a plurality of ratchet gear teethengageable with said one gear tooth on said indexing cylinder.

6. A safety device for preventing the loading of a mortar round into abarrel already containing a mortar round as set forth in claim 4 havingmeans for moving said one gear tooth on said indexing cylinder intoengagement with said teeth on said locking cylinder.

1. A safety device for preventing the loading of a mortar round into abarrel already containing a mortar round comprising, a housing adaptablefor mounting to the outside of a morTar barrel having a slot adjacent toits muzzle end, a first bell crank pivotally attached to said housinghaving first and second arms, a second bell crank pivotally attached tosaid first arm of said first bell crank and having a tripping armextending through said slot of said barrel and having a driving arm, anindexing cylinder rotatably mounted in said housing, a locking cylinderrotatably mounted in said housing and having a plurality of ratchetnotches, said locking cylinder having means for intermittently engagingsaid indexing cylinder, an indexing arm pivotally attached to saidhousing having one end engageable with said indexing cylinder and oneend engageable with said driving arm of said second bell crank, aratchet arm pivotally attached to said housing having one end engageablewith said ratchet notches in said locking cylinder and one endengageable with said second arm of said first bell crank, and stop meansfor limiting the amount of rotation of said locking cylinder.
 2. Asafety device for preventing the loading of a mortar round into a barrelalready containing a mortar round as set forth in claim 1 wherein saidstop means includes a first stop attached to said locking cylinder andsecond and third stops attached to said housing, said first stop beingmovable between said second and third stop.
 3. A safety device forpreventing the loading of a mortar round into a barrel alreadycontaining a mortar round as set forth in claim 2 wherein said thirdstop includes a stationary member and a movable member and means forselecting either said stationary member or said movable member to beengaged by said first stop on said locking cylinder.
 4. A safety devicefor preventing the loading of a mortar round into a barrel alreadycontaining a mortar round as set forth in claim 2 having spring meansfor biasing said locking cylinder so that said first stop engages saidsecond stop.
 5. A safety device for preventing the loading of a mortarround into a barrel already containing a mortar round as set forth inclaim 1 wherein said indexing cylinder has one gear tooth and saidlocking cylinder has a plurality of ratchet gear teeth engageable withsaid one gear tooth on said indexing cylinder.
 6. A safety device forpreventing the loading of a mortar round into a barrel alreadycontaining a mortar round as set forth in claim 4 having means formoving said one gear tooth on said indexing cylinder into engagementwith said teeth on said locking cylinder.